Effects of Salinity on Phenolic Compounds in Tolerant and Sensitive Grapes

Abstract

Salinity is a major environmental stress and grape is classified as a moderately sensitive plant to salinity. Plants have anti-oxidative systems involving antioxidant enzymes and secondary metabolites like phenolic compounds. The aim of this study was to examine the salinity induced alterations, PAL enzyme activity and total phenolics contents in four grape genotypes. In this study two tolerant (Gharashani and H6) and two sensitive (Shirazi and GhezelUzum) grapes-according to screening experiments under salinity-were selected. 50 mM NaCl was used for salinity treatment. Total phenolics content and phenylalanine ammonia-lyase (PAL) activity increased in all the genotypes under salinity. A positive significant correlation (P<0.01, r>0.8) was observed between total phenolics and PAL activity in leaves and roots of grapes. Ten phenolic acids including hydroxybenzoic acid and hydroxycinnamic acid derivatives were analyzed. Our tolerant and sensitive genotypes showed main differences in phenolic compounds accumulation under salinity. Some compounds like gallic, syringic and p-coumaric acids accumulated higher in tolerant genotypes and others like vanillic, caffeic and sinapic acids accumulated in sensitive genotypes. Considering our results it seems that syringic and p-coumaric acids-that was higher in leaves and roots of tolerant genotypeshad a key role in salinity tolerance.

Influence of Moderate to High Salinity on the Phytochemical Profiles of Two Salinity-Tolerant Spinach Genotypes

“…Furthermore, exposure to salinity for a prolonged time was previously reported as having a significant impact on phytochemical content . In grapevine, the content of the phenolic compound (rutin) in leaves and roots of four genotypes increased initially after treatment for 24 h with 50 mM NaCl (equivalent to an EC iw of 5.0 dS m –1 ) but decreased after 7 and 14 days . In the study presented here, we evaluated the effect of salinity in spinach leaves, which were collected after cultivation and irrigation with saline waters for 28 days.…”

“…53 The severity of the salinity response is also influenced by other environmental factors such as temperature, radiation, humidity, and air pollution. 55 Furthermore, exposure to salinity for a prolonged time was previously reported as having a significant impact on phytochemical content. 54 In grapevine, the content of the phenolic compound (rutin) in leaves and roots of four genotypes increased initially after treatment for 24 h with 50 mM NaCl (equivalent to an EC iw of 5.0 dS m −1 ) but decreased after 7 and 14 days.…”

“…54 In grapevine, the content of the phenolic compound (rutin) in leaves and roots of four genotypes increased initially after treatment for 24 h with 50 mM NaCl (equivalent to an EC iw of 5.0 dS m −1 ) but decreased after 7 and 14 days. 55 In the study presented here, we evaluated the effect of salinity in spinach leaves, which were collected after cultivation and irrigation with saline waters for 28 days. The results showed a gradual decrease in both polyphenol and phenolic acid content in plants irrigated with high-salinity water compared to control (Figure 4A,B).…”

“…It has been reported that an increased irrigation water salinity decreases in the rate of growth resulting in a shorter stature and smaller leaves in artichoke and cardoon genotypes . The severity of the salinity response is also influenced by other environmental factors such as temperature, radiation, humidity, and air pollution . Furthermore, exposure to salinity for a prolonged time was previously reported as having a significant impact on phytochemical content .…”

The metabolite vanillic acid regulates Acinetobacter baumannii surface attachment

“…These strains were grown in M9 minimal medium with 0.5 mM VA as a sole carbon source and their growth compared to WT. The VA concentration we used is lower than the VA concentrations found in-planta (~0.8-1 mM; Mohammadkhani, 2018). We measured both the number of viable cells as colony forming units as well as the remaining VA in the growth medium.…”